Electrical device having boardless electrical component mounting arrangement

Abstract

An electrical device such as an LED light assembly includes a conductive circuit and one or more electrical components connected to the circuit. The electrical components and the circuit are at least partially overmolded with a thermoplastic polymer material to encapsulate the components. The material utilized to cover the circuit and/or electrical components may also be utilized to form a housing or other structure of a finished part.

The invention claimed is: 
     
       1. A method of forming an electrical device, the method comprising:
 cutting a sheet of conductive material to form a circuit having at least two electrically conductive circuit elements, each having first and second opposite sides; 
 securing at least one electrical component to the first sides of the circuit elements; 
 positioning the circuit and electrical component in a first mold cavity having a first shape; 
 molding thermoplastic polymer material around the electrical component while it is in the first mold cavity to encapsulate the electrical component in a protective enclosure of polymer material and define an intermediate light assembly, the protective enclosure having a first portion in contact with the first sides of the conductive circuit elements around the electrical component, the protective enclosure having peripheral edge portions extending around at least a portion of the electrical component; 
 positioning the circuit element and electrical component in a second mold cavity having a second shape that is substantially different than the first shape; 
 molding thermoplastic polymer material over at least a portion of the protective enclosure while at least a substantial portion of the intermediate light assembly is disposed in the second mold cavity. 
 
     
     
       2. The method of  claim 1 , wherein:
 the first sides of the conductive circuit elements define generally flat first surface portions; 
 the peripheral edge portions extend to the flat first surface portion and define a peripheral edge surface that is transverse to the flat surface portion. 
 
     
     
       3. The method of  claim 2 , wherein:
 an exposed portion of the first surface portion is not covered by the protective enclosure of polymer prior to positioning the circuit and electrical component in the second mold cavity; and including: 
 molding thermoplastic polymer material over the exposed portion. 
 
     
     
       4. The method of  claim 3 , wherein:
 the first mold cavity is shaped to mold additional thermoplastic polymer material over at least a substantial portion of the first sides of the conductive circuit elements, wherein the additional thermoplastic material includes an edge portion that is spaced apart from the protective enclosure to define a groove extending around the electrical component. 
 
     
     
       5. The method of  claim 4 , wherein:
 the groove formed by the first mold cavity is generally C-shaped in plan view, and wherein a bridge of polymer material extends from the additional polymer material to the protective enclosure. 
 
     
     
       6. The method of  claim 4 , wherein:
 the groove defines a base surface, and at least a portion of the base surface comprises exposed conductive material. 
 
     
     
       7. The method of  claim 1 , wherein:
 the step of securing at least one electrical circuit component includes soldering the circuit component to the circuit element. 
 
     
     
       8. The method of  claim 1 , wherein:
 the step of securing at least one electrical circuit component includes deforming the conductive circuit element to crimp the circuit component to the conductive circuit element. 
 
     
     
       9. The method of  claim 1 , wherein:
 the electrical component comprises an LED, and the electrical device comprises a light. 
 
     
     
       10. The method of  claim 9 , including:
 molding a light-control feature over the LED utilizing the thermoplastic material. 
 
     
     
       11. The method of  claim 9 , wherein:
 at least one additional electrical component in addition to the LED is secured to the circuit element; and 
 a protective enclosure of thermoplastic polymer material is molded over the additional electrical component. 
 
     
     
       12. The method of  claim 9 , wherein:
 the enclosure is generally dome-shaped. 
 
     
     
       13. The method of  claim 1 , wherein:
 the electrical component comprises an integrated circuit having a generally quadrilateral perimeter; 
 the peripheral edge of the enclosure of polymer material has a generally quadrilateral shape. 
 
     
     
       14. The method of  claim 1 , including:
 forming a first generally flat portion of the conductive circuit element; 
 forming a second portion of the conductive circuit element that extends transversely from the first portion; and 
 molding polymer material over at least a substantial portion of the first and second portions of the conductive circuit element. 
 
     
     
       15. The method of  claim 14 , wherein:
 the electrical device comprises a light, and the electrical component comprises an LED that is secured to the first portion of the conductive circuit element. 
 
     
     
       16. The method of  claim 14 , including:
 forming a third portion of the conductive circuit element that extends transversely from the second portion; 
 forming at least two prongs that extend from the third portion; and 
 molding a receptacle in the form of a tubular wall forming a cavity having an open outer end, wherein the prongs are disposed in the cavity. 
 
     
     
       17. The method of  claim 1 , wherein:
 the conductive circuit element defines an outer edge; and including: 
 molding thermoplastic material to form a mounting flange that extends outwardly from the outer edge. 
 
     
     
       18. The method of  claim 1 , wherein:
 the electrical device includes first and second opposite sides, and a periphery extending around the electrical device; and including: 
 molding thermoplastic polymer material to form at least a portion of the periphery, wherein a substantial portion of the periphery is non-linear. 
 
     
     
       19. The method of  claim 18 , wherein:
 a substantial portion of the periphery is curved. 
 
     
     
       20. The method of  claim 19 , wherein:
 the electrical device comprises a disk-shaped light having a circular periphery. 
 
     
     
       21. The method of  claim 20 , wherein:
 a plurality of the electrical components comprise LEDs; and wherein: 
 the first side of the electrical device includes a generally planar surface portion, and a plurality of discrete convex raised portions, aligned with the LEDs, and wherein the raised portions protrude outwardly from the planar surface portion. 
 
     
     
       22. A method of forming an electrical device, the method comprising:
 forming a circuit having at least two electrically conductive circuit elements that are spaced apart to define gaps between the two electrically conductive circuit elements, and wherein the two electrically conductive circuit elements are initially interconnected by connecting portions that extend across the gaps and physically interconnect the two electrically conductive circuit elements, each electrically conductive circuit element having first and second opposite sides; 
 securing at least one electrical component to the first sides of the circuit elements; 
 forming an intermediate assembly by molding protective thermoplastic polymer material around the one electrical component to at least partially cover the one electrical component with the polymer material; 
 allowing the protective thermoplastic polymer material to solidify; 
 cutting the connecting portions such that the electrically conductive circuit elements are disconnected from one another; 
 molding additional thermoplastic polymer material over at least a portion of the protective thermoplastic polymer material; and 
 allowing the additional thermoplastic polymer material to solidify. 
 
     
     
       23. The method of  claim 22 , including:
 providing a mold defining a first mold cavity; 
 positioning at least a portion of the two electrically conductive circuit elements and the one electrical component in the first mold cavity; and 
 molding protective thermoplastic polymer material in the first mold cavity. 
 
     
     
       24. The method of  claim 23 , including:
 forming at least one opening through at least one of the two electrically conductive circuit elements; 
 providing the mold with a locating member; 
 positioning the portion of the two electrically conductive circuit elements and the one electrical component in the first mold cavity with the locating member in engagement with the one opening. 
 
     
     
       25. The method of  claim 22 , wherein:
 the two electrically conductive circuit elements are formed from sheet metal. 
 
     
     
       26. The method of  claim 22 , wherein:
 molding protective thermoplastic polymer material includes encapsulating the one electrical component with thermoplastic polymer material. 
 
     
     
       27. The method of  claim 22 , wherein:
 the first sides of the first and second electrically conductive circuit elements have generally flat first side portions that are spaced apart to form a gap; 
 the one electrical component is secured to the generally flat first side portions with the one electrical component extending across the gap; and 
 the protective thermoplastic polymer material is formed into a protective enclosure extending at least partially over and around the one electrical component and in contact with the first sides of the first and second electrically conductive members. 
 
     
     
       28. The method of  claim 27 , wherein:
 the protective enclosure is formed to include a peripheral surface portion extending around the one electrical component and transversely away from the generally flat first side portions of the first and second electrically conductive circuit elements. 
 
     
     
       29. The method of  claim 28 , wherein:
 the peripheral surface portion intersects the flat first side portions to define a curved edge when viewed along an axis that is normal to the flat first side portions. 
 
     
     
       30. The method of  claim 29 , wherein:
 the protective thermoplastic polymer material is formed to include first thermoplastic polymer material extending over at least a portion of the first sides of the first and second electrically conductive circuit elements adjacent the protective enclosure, wherein the first thermoplastic polymer material is spaced apart from the protective enclosure to form a gap, and including thermoplastic polymer material interconnecting the first thermoplastic polymer material and the protective thermoplastic polymer material. 
 
     
     
       31. The method of  claim 30 , including:
 providing a mold cavity having a first portion that is utilized to form the first thermoplastic polymer material, and a second portion that is utilized to form the protective enclosure of thermoplastic polymer material, and a connecting portion forming a passageway extending between and fluidly interconnecting the first and second portions of the mold cavity; and: 
 introducing molten thermoplastic material into the first portion of the mold cavity, and causing the molten thermoplastic polymer material to flow from the first portion of the mold cavity through the passageway and into the second portion of the mold cavity. 
 
     
     
       32. The method of  claim 31 , wherein:
 the passageway restricts flow of molten thermoplastic polymer material from the first mold cavity portion to the second mold cavity portion, and prevents dislodgement of the one electrical component from the first and second electrically conductive circuit elements. 
 
     
     
       33. The method of  claim 32 , wherein:
 the passageway has a cross-sectional area of approximately 0.0056 square inches. 
 
     
     
       34. The method of  claim 31 , wherein:
 the passageway has a cross-sectional shape that is approximately semi-circular. 
 
     
     
       35. The method of  claim 31 , wherein:
 the passageway defines a first volume; and 
 the second portion of the mold cavity defines a second volume that is much greater than the first volume. 
 
     
     
       36. The method of  claim 31 , wherein:
 the mold cavity comprises a first mold cavity; and including:
 providing a second mold cavity; 
 removing the intermediate assembly from the first mold cavity; 
 positioning the intermediate assembly in the second mold cavity; and 
 introducing molten thermoplastic polymer material into the second mold cavity to thereby mold the additional thermoplastic polymer material over at least a portion of the protective thermoplastic polymer material. 
 
 
     
     
       37. The method of  claim 22 , including:
 providing first and second electrical connectors that are electrically connected to the two electrically conductive circuit elements; and 
 forming the thermoplastic polymer material such that the first and second electrical connectors protrude outside the additional thermoplastic material after it solidifies. 
 
     
     
       38. The method of  claim 37 , wherein:
 the first and second electrical connectors comprise prongs. 
 
     
     
       39. The method of  claim 38 , wherein:
 the first and second electrically conductive members are made from sheet metal; and 
 the prongs are formed integrally from the sheet metal. 
 
     
     
       40. A method of forming an electrical device, the method including:
 mechanically cutting sheet metal to form first and second conductive circuit elements having first and second sides and defining gaps between the first and second circuit elements; 
 securing a plurality of electrical components to the first and second conductive circuit elements; 
 providing a mold cavity having a first cavity portion and a second cavity portion, and a passageway defining a shape and interconnecting the first and second cavity portions; 
 molding first thermoplastic polymer material onto at least a portion of the first sides of the first and second conductive circuit elements by introducing molten thermoplastic polymer material into the first cavity portion; 
 causing molten thermoplastic polymer material to flow through the passageway from the first cavity portion to the second cavity portion to thereby mold protective thermoplastic polymer material over at least a portion of the first sides of the first and second conductive circuit elements; 
 permitting the thermoplastic polymer material in the mold cavity to solidify; and wherein: 
 the thermoplastic polymer material forms enclosures that extend at least partially over and around the electrical components and contact the first sides of the first and second conductive circuit elements, and wherein the enclosures are connected to the first thermoplastic polymer material by thermoplastic polymer material forming a connector having a shape corresponding to the shape of the passageway. 
 
     
     
       41. The method of  claim 40 , wherein:
 the enclosure is generally dome-shaped. 
 
     
     
       42. The method of  claim 41 , wherein:
 the enclosure has a circular perimeter. 
 
     
     
       43. The method of  claim 40 , wherein:
 the first thermoplastic polymer material and the thermoplastic polymer material forming the enclosure are spaced apart to define a gap therebetween. 
 
     
     
       44. The method of  claim 43 , wherein:
 the gap extends around the enclosure and is generally C-shaped. 
 
     
     
       45. The method of  claim 40 , wherein:
 the enclosure has a generally quadrilateral perimeter. 
 
     
     
       46. The method of  claim 40 , wherein:
 the mold cavity comprises a first mold cavity; including: 
 providing a second mold cavity; 
 removing the first and second conductive circuit elements from the first mold cavity; 
 positioning at least a portion of the first and second conductive circuit elements in the second mold cavity; and 
 molding additional thermoplastic polymer material over at least one of the enclosures by introducing molten thermoplastic polymer material into the second mold cavity.